Aircraft pipe joints, for example in aircraft fuel systems, often include a washer disposed between a first pipe end and a second pipe end. The first pipe end and second pipe end are typically connected with at least one nut disposed on the outer surface of either the first pipe end or second pipe end. For aircraft pipe joints, especially in aircraft fuel systems, it is essential that there is no leakage from the pipe joint into the surrounding environment. Such leakage can damage the aircraft, possibly in a serious manner. Pipe joints, for example slat track drain hose connections, may require “double locking” in order to comply with aircraft safety regulations. Such a double locking arrangement may be provided by first locking the pipe joint by the engagement of the pipe connectors. Such an arrangement may be, for example, a nut on disposed on the outer surface of a pipe end. Wire locking may be used to provide a secondary lock on the drain hoses.
However, wire locking may result in fragments of wire entering the aircraft fuel filter system and causing damage.
The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved aircraft pipe coupling arrangement.